Occupy London are planning another demonstration this afternoon in Parliament Square, in the shadow of the Houses of Parliament.

The demonstration will go ahead in defiance of a ban by the Mayor of London, Boris Johnson, on protests in the square. The protest takes place on Democracy Day, which this year coincides with the 750th anniversary of the world's first elected parliament.

Following efforts by London Mayor Boris Johnson to bar protestors from the square, the civil rights campaigning organisation Liberty has filed a Judicial Review against the ban. The protesters say they are keen to see whether the Mayor will continue to deny them access to Parliament Square, now that he has been warned by Liberty that his decision to fence it off is likely to be illegal.

Today's demonstration is part of an ongoing series that began in October with a two-week occupation of the square that resulted in a number of arrests. The demonstration is intended to highlight corporate influence over foreign policy, with regard to arms sales, contracts relating to war and nuclear weapons.

It will feature workshops by groups including the Campaign Against Arms Trade, as well as an Occupy assembly. Occupy London says it is committed to peaceful direct action.

The Occupy demonstration begins at 3pm and will follow from an earlier CND demonstration against the UK's Trident nuclear missile deterrent, which starts at noon outside the Ministry of Defence.

The CND event is called "Wrap up Trident" and peace activists plan to wrap the Ministry of Defence and MP's offices in a "peace scarf" knitted by thousands of supporters.

Occupy London spokesperson David Dewhurst said that he hoped there would be no violence today.

In answer to the charge that the movement peaked with its encampment next to St Paul's cathedral in the winter of 2011/2012 and has had little impact on mainstream politics, he said: "There has been a certain amount of political nodding" citing statements by George Osborne and David Cameron condemning tax evasion by large corporations.